Drawing using the Mouse

public class MousePaint extends Frame implements MouseMotionListener
    {
     private int x1, y1, x2, y2;
     public MousePaintII()
         {
         addWindowListener(new WindowAdapter()
             {
             public void windowClosing(WindowEvent we)
                 {
                 dispose();
                 System.exit(0);
             }
         });
         addMouseMotionListener(this);
         setBounds(50,50,400,250);
         setVisible(true);
     }
     public static void main(String[] argv)
         {
         new MousePaintII();
     }
     public void update(Graphics g)
         {
         paint(g);
     }
     public void paint(Graphics g)
         {
         g.setColor(Color.black);
         g.drawLine(x1, y1, x2, y2);
     }
     public void mouseDragged(MouseEvent me)
         {
         me.consume();
         int x = me.getX();
         int y = me.getY();
         if ( x1 == 0 )
             {
             x1 = x;
         }
         if ( y1 == 0 )
             {
             y1 = y;
         }
         x2 = x;
         y2 = y;
         repaint();
         x1 = x2;
         y1 = y2;
     }
     public void mouseMoved(MouseEvent me)
     { }
}